Why Hydrogen?

There are many reasons that make hydrogen a good secondary fuel:

Large Source--Hydrogen is very abundant, especially in the form of water, which cover most of the earth. It can be easily separated by electrolysis at a 67% efficiency.

Clean Combustion--When recombining the hydrogen and oxygen through combustion the only product is water and a great deal of energy. Only small amounts of nitrogen oxides are produced during combustion because the air is heated so much. Compared to fossil fuel combustion, this pollution is very small.

Large Energy Density--The energy density of hydrogen is 38 khw/kg. Gasoline is considered to be very energy dense but its density is only 14 khw/kg, hydrogen more than doubles this. A high energy density is desirable because hydrogen needs to be easy and economically viable to store and transport.

Economic Storage--For use as a secondary fuel, hydrogen must be stored as a liquid (20 K or -253 C). The energy density is then a thousand times higher than gas form. The cryogenic hydrogen facility needed to reach these incredibly low temperatures (20 K) is much less expensive than a pumped hydro facility (dams pump water to a higher elevation to pass through the dam later when the energy is needed).

Fuel Cell Possibilities--There are huge advances and recent applications with fuel cells. These use a catalyst to react oxygen and hydrogen instead of heat. A cell can achieve an 85% efficiency in the lab, but has not been tested enough on a large scale. There are many possible applications for the fuel cell.

Transportation--Existing natural gas lines could be used for hydrogen transportation. Three times the amount of natural gas of hydrogen is needed for the same energy requirement, but hydrogen can be pumped three times as fast. Also, pipelines would be more efficient and cheaper than sending electricity great distances.

Renewable Energies--One major problem with renewable resources is the randomness. The sun does not shine all the time and the wind blows in gusts. A hydrogen system could be used to collect whatever energy could be obtained from solar, hydro, or wind and then used whenever that energy was needed.

These make hydrogen a resource that needs to be researched and employed more in the future. Electricity is clean and fast, but cannot be effectively stored. Electricity can produce hydrogen from water and hydrogen can produce electricity by forming water. In this way, hydrogen can be stored until needed and then converted to electricity for an end use.

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